Patent Literature 1 mentions a multi-axis tapping device that includes five tapping assemblies, in which spindles driven to rotate by spindle motors are respectively provided, and a frame that supports the five tapping assemblies laterally in a row and is reciprocatingly driven by a feed motor, the spindle motors being individually rotated in synchronization with the feed motor to perform machining of tap holes in a workpiece using taps attached to the distal ends of the spindles. Consequently, according to Patent Literature 1, to change the disposition of the spindles according to the change of the portion of the workpiece being tapped, a through-hole formed in a frame member and a holding plate only have to be changed to those corresponding to the portion of the workpiece being machined to change the disposition of the tapping assemblies that bear the spindles. Therefore, the number of components necessary for the change is reduced.